Veins of pelvis
Three major veins provide venous drainage from the pelvic walls and viscera. They are the external iliac vein, internal iliac vein, and the common iliac vein, which is formed on each side of the body by the fusion of the external and internal iliac veins.
Ultimately venous blood from the pelvis is collected by the inferior vena cava, which is formed by merging of the right and left common iliac veins. The inferior vena cava carries blood to the right atrium of the heart.
Note: The veins of the pelvis correspond to the major pelvic arteries and share their names.